Akermanite Yang H, Hazen R M, Downs R T, Finger L W Physics and Chemistry of Minerals 24 (1997) 510-519 Structural change associated with the incommensurate-normal phase transition in akermanite, Ca2MgSi2O7, at high pressure Sample: P = 3.79 GPa _database_code_amcsd 0008036 7.7494 7.7494 4.9328 90 90 90 P-42_1m atom x y z Biso B(1,1) B(2,2) B(3,3) B(1,2) B(1,3) B(2,3) Ca .3340 .1660 .5050 1.04 .0042 .0042 .0112 .0016 .0006 .0006 Mg 0 0 0 .76 .0019 .0019 .0138 0 0 0 Si .1406 .3594 .9354 .53 .0026 .0026 .0038 .0005 -.0002 -.0002 O1 .5 0 .1835 1.2 .0062 .0062 .0074 -.0029 0 0 O2 .1396 .3604 .2601 1.5 .0050 .0050 .0217 .0015 -.0017 -.0017 O3 .0822 .1839 .7783 1.1 .0062 .0022 .0134 -.0007 .0021 -.0016